title: Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis.
abstract: OBJECTIVE
  To determine if the use of ultrasound guidance (vs non-ultrasound techniques) improves the success rate of nerve blocks.
  
  
  METHODS
  Meta-analysis of randomized controlled trials (RCTs) in the published literature.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  16 RCTs of patients undergoing elective surgical procedures were studied. Patients underwent ultrasound-guided or non-ultrasound techniques (nerve stimulation, surface landmark) for peripheral nerve blocks. Success rates were measured.
  
  
  RESULTS
  Ultrasound guidance (vs all non-ultrasound techniques) was associated with a significant increase in the success rate of nerve blocks [relative risk (RR) = 1.11 (95% confidence interval [CI]: 1.06 to 1.17, P < 0.0001]). When compared with nerve stimulator techniques only, ultrasound guidance was still associated with an increase in the success rate (RR = 1.11 [95% CI: 1.05 to 1.17, P = 0.0001]). For specific blocks, ultrasound guidance (vs all non-ultrasound) was associated with a significant increase in successful brachial plexus (all) nerve blocks (RR = 1.11 [95% CI: 1.05 to 1.20, P = 0.0001]), sciatic popliteal nerve block (RR = 1.22 [95% CI: 1.08 to 1.39, P = 0.002]) and brachial plexus axillary nerve block (RR = 1.13 [95% CI: 1.00 to 1.26, P = 0.05]) but not brachial plexus infraclavicular nerve block (RR = 1.25 [95% CI: 0.88 to 1.76, P = 0.22]).
  
  
  CONCLUSIONS
  Ultrasound-guided peripheral nerve block is associated with an increased overall success rate when compared with nerve stimulation or other methods. Ultrasound-guided techniques also increase the success rate of some specific blocks.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, MD 21287, USA.
authors.forename: Harold J
authors.initials: HJ
authors.lastname: Gelfand
authors.forename: Jean-Pierre P
authors.initials: JP
authors.lastname: Ouanes
authors.forename: Maggie R
authors.initials: MR
authors.lastname: Lesley
authors.forename: Phebe S
authors.initials: PS
authors.lastname: Ko
authors.forename: Jamie D
authors.initials: JD
authors.lastname: Murphy
authors.forename: Shawn M
authors.initials: SM
authors.lastname: Sumida
authors.forename: Gillian R
authors.initials: GR
authors.lastname: Isaac
authors.forename: Kanupriya
authors.initials: K
authors.lastname: Kumar
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wu
mesh_terms: D000765:Anesthesia, Conduction / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage; D001917:Brachial Plexus; D004599:Electric Stimulation Therapy / Q000379:methods; D006801:Humans; D009407:Nerve Block / Q000379:methods*; D010525:Peripheral Nerves / Q000000981:diagnostic imaging; D016032:Randomized Controlled Trials as Topic; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000779:Anesthetics, Local